Example of pigment stability after UV ageing.
See more about UV weathering here.
In this example the client had several years of moulding experience with traditional non polymeric materials. They had already conducted some initial development work in house using silicone based materials and had produced some prototypes.
Example of finished product with new paint and new materials
The products were to be used in an outdoor environment and hence the weathering characteristics were critical. Materials Technology conducted some initial accelerated UV weathering on the products which highlighted a number of potential issues with the products in service. Some of these problems included stability of the pigments used, bonding and robustness of the exteriour layers and exudation from the base material resulting in a geasy layer and deterioration in properties.
Example of new slicone based paints in range of colours
Materials Technology conducted a review of the moulding materials and were able to select a range of suitable materials that exhibited little or no exudation under normal weathering conditions. A range of pigments were then screened for their weathering characteristics and a range of more stable pigments were selected.
A review of bonding technology was also conducted on behalf of the client and and specific recommendations for their processes were made. Finally new silicone based paint systems were formulated in the laboratory which allowed the client to formulate their own colours and formulations as and when required. When these were combined with the new resin systems and bonding technology and hard wearing weather resistant product was obtained without any compromise in the moulding technology that the client was familiar with.